L E E H U P P E R I C H , P . E .

M E C H A N I C A L E N G I N E E R

Unique Swing Span Design for the St. Ann Bridge in Houma, Louisiana

Presentation Overview

I. Project Location and General Information II. Former St. Ann Bridge III. New St. Ann Bridge a. Bridge Type & Design Criteria b. Structural Design Features c. Mechanical Design Features IV. Field Photographs V. Construction Cost VI. Partners

I. Project Location & General Information

S.P. No. H.006318 (713-55-0100)

St. Ann Bridge Replacement Over Bayou Terrebonne, Terrebonne Parish, Houma LA

Federal Aid Off-System Highway Bridge Program

Bridge Site Bridge Site

II. Former St. Ann Bridge

The former St. Ann bridge was a 118’ single lane, equal arm swing bridge, circa 1960. The bridge deck is

supported by a center pylon with steel stay rods attached to the floor beams. The sub-structure consists of

timber piles and timber bents.

II. Former St. Ann Bridge

- Single lane with no shoulders

- Timber deck with steel plate runners

- 5 ton posting

- Number of openings: 0-30 per year.

III. New St. Ann Bridge

Plan – New Swing Span and Approaches Design Directives

90’-0” (60’/30’) unequal arm swing span bridge on a new alignment.

35’-0” horizontal clearance for marine navigation.

30’-0” clear roadway (two 12’-0” traffic lanes, two 3’-0” shoulders).

Minimal control system - infrequently operated bridge.

Movable traffic barriers (vertical type).

III a. New St. Ann Bridge

Design Specifications

AASHTO Standard Specifications for Highway Bridges, 2002.

AASHTO Standard Specifications for Movable Bridges, 1988.

Construction Specifications

LADOTD Standard Specifications for Roads and Bridges, 2006.

Elevations

Datum used - NAVD 88.

Design Criteria

Live load HS-20-44 Truck or Lane Load, HS-18 Truck.

Profile – New Swing Span and Approaches

III b. Structural - Framing

III b. Structural - Pivot Girder

Unique Structural Elements

- Double Pivot Girder

- No Center Wedges

- Counterweights placed on the

west main girder to offset the weight

of the access platform & HPU weight

III b. Structural – Shop Assembly

III c. Machinery Layout

PLAN – MACHINERY LAYOUT

III c. Movable Traffic Barriers

III c. Pivot Pier Machinery

SECTION THRU PIVOT GIRDER

III c. Pivot Bearing

PIVOT BEARING ASSEMBLY

III c. Hydraulic Machinery

NORTH REST PIER

SOUTH REST PIER

HYDRAULIC MOTOR AND PINION ASSEMBLY

HYDRAULIC POWER UNIT

ROLLER WEDGE

ROLLER WEDGE

HYDRAULIC MACHINERY LAYOUT

III c. HPU & Controls

(HPU) – TOP VIEW

HPU & MOTOR ASSEMBLY

VIEW A-A: ELECTRICAL PANEL

III c. Control Panel

CONTROL PANEL LAYOUT

Hydraulic System:

Hydraulic Motor : SAI GM3 – 1000 Radial Piston Type

Hydraulic Displacement : 1.369 gal/rev

Max Flow Rate: 20 gpm

HPU System Pressure (Compensator Pressure) = 2,200 psig

Operating Pressure – Roller Wedges = 500 – 1,000 psig

Operating Pressure – Span Drive Motor = 900 – 1,800 psig

All hydraulic equipment rated for a minimum of 3,000 psi

Electric Motor:

30 hp Squirrel Cadge Induction Motor TEFC

In-Line Gear Reducer:

5.25:1 Reduction

Pinion Velocity:

13.88 rpm

Span Velocity:

0.58 rpm

III c. Shop Testing Hydraulic Machinery

IV. New St. Ann Bridge – East Elevation

IV. New St. Ann Bridge – Open Position

IV. Hydraulic Motor, Gear Reducer, Brake & Pinion

IV. HPU – Control Panel & HPU Access

IV. Counterweight & South Rest Pier

IV. New St. Ann Bridge – West Elevation

IV. New St. Ann Bridge - Roller Wedge

IV. New St. Ann Bridge - Pivot Pier

IV. New St. Ann Bridge - Pivot Bearing

IV. New St. Ann Bridge - Site Plan

V. Construction Cost

Construction

Mobilization: $400,000

Removal of Existing Bridge $134,500

Roadway $333,756

Bridge $2,065,864

Electrical System $240,000

Movable Bridge Machinery $890,000

Movable Traffic Barriers $150,000

Total Construction Cost: $4,214,120

VI. Design and Construction Partners

Design was completed in 2010 & let on June 29, 2011.

Construction was completed in early 2014.

Project Manager: Gary Pentek, P.E. (LaDOTD)

Road Design: James Ledet, P.E. (T. Baker Smith)

Structural Design: Colby Guidry, P.E. (Huval)

Mechanical & Electrical Design: Malcolm Huval, P.E. (Huval)

Pier Review & CRES: Lee Hupperich, P.E. (Huval)

Project Engineer: Larry Langenstein (ECM)

Contractor: Van Bailey & John Housey (Coastal Bridge Co.)

Fabricators:

Hydraulic Machinery: Supreme Integrated Technology

Bridge Structural Steel & Machinery: Hardie-Tynes

Electrical System: Coastal Bridge Co.

L E E H U P P E R I C H , P E

M E C H A N I C A L E N G I N E E R

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